In reply to a post by Hatari:

Lemzip,

Thanks, What I suspect is your interference has changed because the height Ionosphere has changed as it does between winter and summer. Radio waves bounce off the Ionosphere hence its height depends on whether they reach you or miss you. In addition, this evening the air pressure has risen quite sharply, this also affects whether you get interference on the TV, hence the bright light, although it could also be a set fault.

I would guess come next May your BB problem will have died and your sync level picked up and come the winter it will be back.

Do you live on the south coast by any chance?

It has got nothing at all to do with the height of the layer, and there is no real winter/summer change. The layer that reflects MW radio signals is broken down by sunlight, and since the layer over us receives less sunlight in the winter, the destructive effect on the layer is less this time of year. As the amount of sunlight that the layer is exposed to increases as spring/summer approaches, the effects on the layer will increase.

In reply to a post by zebedeee:

It has got nothing at all to do with the height of the layer, and there is no real winter/summer change. The layer that reflects MW radio signals is broken down by sunlight, and since the layer over us receives less sunlight in the winter, the destructive effect on the layer is less this time of year. As the amount of sunlight that the layer is exposed to increases as spring/summer approaches, the effects on the layer will increase.

Sorry to disagree with you, but as someone who made use of the variation of the various layers for communications purposes, you�re not correct. The height of the reflecting layer determines where the signal will come back to earth. It acts similar to the way a mirror reflects light. Hence, the strength of a reflected signal varies.